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path: root/fs/smb/client/transport.c
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2024-02-01smb: client: increase number of PDUs allowed in a compound requestPaulo Alcantara
With the introduction of SMB2_OP_QUERY_WSL_EA, the client may now send 5 commands in a single compound request in order to query xattrs from potential WSL reparse points, which should be fine as we currently allow up to 5 PDUs in a single compound request. However, if encryption is enabled (e.g. 'seal' mount option) or enforced by the server, current MAX_COMPOUND(5) won't be enough as we require an extra PDU for the transform header. Fix this by increasing MAX_COMPOUND to 7 and, while we're at it, add an WARN_ON_ONCE() and return -EIO instead of -ENOMEM in case we attempt to send a compound request that couldn't include the extra transform header. Signed-off-by: Paulo Alcantara <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-23cifs: translate network errors on send to -ECONNABORTEDShyam Prasad N
When the network stack returns various errors, we today bubble up the error to the user (in case of soft mounts). This change translates all network errors except -EINTR and -EAGAIN to -ECONNABORTED. A similar approach is taken when we receive network errors when reading from the socket. The change also forces the cifsd thread to reconnect during it's next activity. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2024-01-23cifs: cifs_pick_channel should try selecting active channelsShyam Prasad N
cifs_pick_channel today just selects a channel based on the policy of least loaded channel. However, it does not take into account if the channel needs reconnect. As a result, we can have failures in send that can be completely avoided. This change doesn't make a channel a candidate for this selection if it needs reconnect. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-11-10cifs: handle when server stops supporting multichannelShyam Prasad N
When a server stops supporting multichannel, we will keep attempting reconnects to the secondary channels today. Avoid this by freeing extra channels when negotiate returns no multichannel support. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-10-31smb: client: fix potential deadlock when releasing midsPaulo Alcantara
All release_mid() callers seem to hold a reference of @mid so there is no need to call kref_put(&mid->refcount, __release_mid) under @server->mid_lock spinlock. If they don't, then an use-after-free bug would have occurred anyways. By getting rid of such spinlock also fixes a potential deadlock as shown below CPU 0 CPU 1 ------------------------------------------------------------------ cifs_demultiplex_thread() cifs_debug_data_proc_show() release_mid() spin_lock(&server->mid_lock); spin_lock(&cifs_tcp_ses_lock) spin_lock(&server->mid_lock) __release_mid() smb2_find_smb_tcon() spin_lock(&cifs_tcp_ses_lock) *deadlock* Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-19cifs: Fix UAF in cifs_demultiplex_thread()Zhang Xiaoxu
There is a UAF when xfstests on cifs: BUG: KASAN: use-after-free in smb2_is_network_name_deleted+0x27/0x160 Read of size 4 at addr ffff88810103fc08 by task cifsd/923 CPU: 1 PID: 923 Comm: cifsd Not tainted 6.1.0-rc4+ #45 ... Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_report+0x171/0x472 kasan_report+0xad/0x130 kasan_check_range+0x145/0x1a0 smb2_is_network_name_deleted+0x27/0x160 cifs_demultiplex_thread.cold+0x172/0x5a4 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 </TASK> Allocated by task 923: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_slab_alloc+0x54/0x60 kmem_cache_alloc+0x147/0x320 mempool_alloc+0xe1/0x260 cifs_small_buf_get+0x24/0x60 allocate_buffers+0xa1/0x1c0 cifs_demultiplex_thread+0x199/0x10d0 kthread+0x165/0x1a0 ret_from_fork+0x1f/0x30 Freed by task 921: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x2a/0x40 ____kasan_slab_free+0x143/0x1b0 kmem_cache_free+0xe3/0x4d0 cifs_small_buf_release+0x29/0x90 SMB2_negotiate+0x8b7/0x1c60 smb2_negotiate+0x51/0x70 cifs_negotiate_protocol+0xf0/0x160 cifs_get_smb_ses+0x5fa/0x13c0 mount_get_conns+0x7a/0x750 cifs_mount+0x103/0xd00 cifs_smb3_do_mount+0x1dd/0xcb0 smb3_get_tree+0x1d5/0x300 vfs_get_tree+0x41/0xf0 path_mount+0x9b3/0xdd0 __x64_sys_mount+0x190/0x1d0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 The UAF is because: mount(pid: 921) | cifsd(pid: 923) -------------------------------|------------------------------- | cifs_demultiplex_thread SMB2_negotiate | cifs_send_recv | compound_send_recv | smb_send_rqst | wait_for_response | wait_event_state [1] | | standard_receive3 | cifs_handle_standard | handle_mid | mid->resp_buf = buf; [2] | dequeue_mid [3] KILL the process [4] | resp_iov[i].iov_base = buf | free_rsp_buf [5] | | is_network_name_deleted [6] | callback 1. After send request to server, wait the response until mid->mid_state != SUBMITTED; 2. Receive response from server, and set it to mid; 3. Set the mid state to RECEIVED; 4. Kill the process, the mid state already RECEIVED, get 0; 5. Handle and release the negotiate response; 6. UAF. It can be easily reproduce with add some delay in [3] - [6]. Only sync call has the problem since async call's callback is executed in cifsd process. Add an extra state to mark the mid state to READY before wakeup the waitter, then it can get the resp safely. Fixes: ec637e3ffb6b ("[CIFS] Avoid extra large buffer allocation (and memcpy) in cifs_readpages") Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-09-15smb3: fix some minor typos and repeated wordsSteve French
Minor cleanup pointed out by checkpatch (repeated words, missing blank lines) in smb2pdu.c and old header location referred to in transport.c Signed-off-by: Steve French <stfrench@microsoft.com>
2023-08-20smb: client: reduce stack usage in smb_send_rqst()Paulo Alcantara
Clang warns about exceeded stack frame size fs/smb/client/transport.c:420:1: warning: stack frame size (1048) exceeds limit (1024) in 'smb_send_rqst' [-Wframe-larger-than] Fix this by allocating a structure that will hold transform header and compound requests. Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-28cifs: do all necessary checks for credits within or before lockingShyam Prasad N
All the server credits and in-flight info is protected by req_lock. Once the req_lock is held, and we've determined that we have enough credits to continue, this lock cannot be dropped till we've made the changes to credits and in-flight count. However, we used to drop the lock in order to avoid deadlock with the recent srv_lock. This could cause the checks already made to be invalidated. Fixed it by moving the server status check to before locking req_lock. Fixes: d7d7a66aacd6 ("cifs: avoid use of global locks for high contention data") Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-06-11smb: remove obsolete comment鑫华
Because do_gettimeofday has been removed and replaced by ktime_get_real_ts64, So just remove the comment as it's not needed now. Signed-off-by: 鑫华 <jixianghua@xfusion.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2023-05-24smb: move client and server files to common directory fs/smbSteve French
Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko and helper modules) to new fs/smb subdirectory: fs/cifs --> fs/smb/client fs/ksmbd --> fs/smb/server fs/smbfs_common --> fs/smb/common Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>